Sixth Day Of Life Research Articles

Metabolic DNA in the hepatocyte nuclei in newborn rats.

The behaviour in time of labelled nuclear DNA in the hepatocytes of newborn rats was studied using autoradiographic and biochemical techniques in two groups of experiments. In the first group H-3-thymidine was injected to the mothers at the 16th day of pregnancy and the amount of labelled DNA was evaluated in the newborns after delivery. In the second group H-3-thymidine was injected to the newborns two hours after birth and the labelled DNA was studied at the same time intervals as the first group. The amount of labelled thymidine incorporated into the first group of animals remains constant for the first three days of life, thereafter a reduction in specific activity of DNA is observed concomitant with an increase of the percentage of labelled nuclei and a decrease of the number of grains per nucleus. These results show that mitotic divisions, which are absent during the first three days of life, take place between the third and sixth days of life. The decrease of the specific activity is therefore due to dilution and not to loss of labelled DNA. In the second group of experiments the DNA labelled with H-3-thymidine shows a decrease by about 30--40% per day during the first three days of life accompanied by a decrease in the number of grains per nucleus without changes in the percentage of labelled nuclei. These data show that DNA synthesized during the first day after birth is metabolically unstable, unlike that synthesized during foetal life.

Influence of previous oral contraception and maternal oxytocin infusion on neonatal jaundice.

A prospective study of serum bilirubin levels on the first and sixth days of life in a series of 181 infants has failed to provide evidence to suggest that previous maternal oral contraception, maternal oxytocin infusion, epidural anaesthesia, or breast-feeding are factors influencing neonatal jaundice.

Pneumococcal Meningitis in Mother and Neonate

Recent reports have stressed several features of meningitis in the newborn period: high mortality rates despite antibiotic therapy, the absence of symptoms and signs of meningeal irritation and the frequency with which enteric bacilli are the causative agent. The observation that obstetrical complications increase the incidence of neonatal meningitis and that the majority of these infants develop their disease before the sixth day of life suggest that the infection is acquired during parturition. The following case is of interest because of the unusual occurrence in both mother and infant of meningitis due to pneumococci, an organism which is an infrequent cause of meningitis in the neonatal period.

An attempt to estimate normal values of peripheral blood in twins at the first, third, and sixth day after delivery.

A total of 26 healthy full-term infants from multiple pregnancies and a control group of 96 infants from single pregnancies, all from the Rzeszow district, were tested. Blood was taken from cranial veins at the first, third, and sixth day of life, always at the same time. All infants were kept under the same conditions. The results of the investigation show that (a) twin infants have lower values of peripheral blood than singleton infants in their first six days after delivery, and (b) the second twin has higher values of peripheral blood as compared with the first one.

Maternal factors in neonatal hypocalcaemia: a study in three ethnic groups.

To assess the significance of various maternal and neonatal factors in the aetiology of neonatal tetany we have investigated the serum calcium, phosphorus, magnesium, and heat-labile alkaline phosphatase of 250 mothers from three ethnic groups at several stages of pregnancy and the serum calcium, phosphorus, and magnesium of many of their infants. Subclinical hypocalcaemia was found to be much commoner in full-term infants on the sixth day of life than is generally appreciated, especially during the winter months and in babies of Asian parents. It is considered that this is a result of high phosphorus loads in artificial milks and is also influenced by maternal vitamin D and possibly calcium intake during pregnancy. The importance of ensuring that Asian women take adequate vitamin D supplements during pregnancy is stressed.

Absence of alteration in puberal onset in male rats following amygdaloid lesioning.

In a previous experiment, bilateral amygdaloid lesions in 4-day-old rats of both sexes unexpectedly produced delayed puberty (judged by vaginal opening) in the females. The onset of puberty (judged by testicular descent) in the males (not studied), however, did not appear to be affected. To investigate the possibility that amygdaloid lesions produce different effects in the sexes, alternate litter mates underwent either bilateral amygdaloid lesioning or a sham operation on the sixth day of life. All rats were reared in diurnal lighting. All males were sacrificed on the day of testicular descent and random females on the day of vaginal opening. Multivariate analysis of covariance revealed no difference between the 2 male groups as regards the day of maturation, body weight, tail length, or testicular, ventral prostate or seminal vesicle weights (p>0.1). However, a multivariate analysis of the female groups, as regards the same first 3 variables, plus ovarian and uterine weights, revealed a significant difference (p<0.005), with a delay in puberty in the lesioned groups confirming previous work. Thus, male and female rat pups do not respond similarly to amygdaloid lesioning. It is possible that differences between the sexes in the degree of maturation of the connections between the stria terminalis afferents and the medial hypothalamic area, as well as those of this circuit with the suprachiasmatic-preoptic area, may account for the divergent effects of amygdaloid lesioning on sexual maturation. {Endocrinology 88: 1272, 1971) I A RECENT study of factors affecting puberaJ onset, this author noted that bilateral amygdaloid lesions in 4-day-old rats of both sexes unexpectedly produced delayed puberty (judged by vaginal opening) in the females (1). This finding was in contrast to the acceleration of puberty reported when bilateral amygdaloid lesions were produced in 18to 20-day-old female rats (2). Furthermore, in the former experiment the onset of puberty (judged by testicular descent) in the male rats (not studied) did not appear to be affected. To investigate the possibility that amygdaloid lesions produce different effects in the sexes the following experiment was performed. Materials and Methods Inbred rats of the Wistar strain were used. Eighty-two pups were randomly chosen from litters of varying size. These animals, comprised of even-numbered groups of litter mates, were exposed daily to an environment of 16 hr of darkness and 8 hr of overhead lighting, yielding 100-150 ft-c at the cage surface. On the sixth day of life alternate members underwent either bilateral amygdaloid lesioning according to the method described elsewhere (1), or a sham operation. This day was chosen to perform the lesioning because physiologic masculinization of the rat brain is completed by day 6 of life (3). Coding for designation was achieved by injecting India ink under the skin of the lateral aspect of one or more legs. Received October 20, 1970. Throughout the experiment water was available ad lib. and a standard comprehensive diet (Purina laboratory chow) was used. The temperature in the room was controlled and kept at approximately 23 C (range 21-25 C). Litters were weaned at age 23 days and, commencing at this age, male young were observed daily for testicular descent without being handled (to obviate testicular retraction). Until a litter was depleted of males, females were left in the cage. To obviate any question about the validity of comparing lesioning performed on the 4th day in the previous experiment (1) with sixth-day lesioning herein described, day of vaginal opening was recorded in 6 lesioned and 7 sham-operated females taken at random from some of the same litters as were used in this experiment. Testicular descent was chosen as a maturational parameter comparable to that of vaginal opening because prior investigation (1, 4, 5) has shown that both events can be similarly affected by a procedure (i.e., pinealectomy) which accelerates the time of puberal onset. All males, and the randomly selected females, reaching puberty were sacrificed with ether the day testicular descent or vaginal opening was discovered, their body weights recorded, and tail length measured. Testes, ventral prostate, seminal vesicles (with coagulating glands), ovaries and uteri were dissected and weighed fresh. Testes and ovaries were fixed in 10% formalin, embedded in paraffin, and 10 n sections stained with hematoxylineosin. The brains were removed in toto and fixed in 10% formalin, embedded in paraffin, cut in 10 M sections, and every fifteenth section mounted and stained with hematoxylin-eosin.

KERNICTERUS: HIGH INCIDENCE IN PREMATURE INFANTS WITH LOW SERUM BILIRUBIN CONCENTRATIONS

During a 2-year period, 1966 and 1967, 485 low birth weight infants were admitted to the special care unit. Sixteen of these infants expired during the third to sixth days of life, and fourteen of them were examined postmortem. Nine of the fourteen infants (64%) were found to have pathologic evidence of kernicterus characterized by yellow staining of one or more areas of the brain with necrosis of brain cells in the stained areas. None had clinical signs of kernicterus. Peak total serum bilirubin concentrations ranged from 9.4 to 15.6 mg/100 ml in the kernicteric group and from 8.8 to 17.2 mg/100 ml in the group without kernicterus. These infants were of extremely low birth weight and short gestational period, and they had very low Apgar scores and the respiratory distress syndrome. Pathologically the infants demonstrated pulmonary atelectasis, hyaline membranes, and pneumonia as their major findings. Extraneural lesions of hyperbilirubinemia were observed in four infants with kernicterus but not in any of the infants without kernicterus. Neuropathological examination revealed a high frequency of intracranial hemorrhage in the kernicteric group in addition to yellow staining and cell necrosis.

Pregnanediol excretion by newly born infants.

VERY FEW studies have been reported concerning pregnanediol excretion in the urine of newborn infants.1-5Roby et al1measured urinary pregnanediol by a gravimetric method in five normal term infants. Normal values of excretion averaged 250μg on the first day of life fell to 46μg by the sixth day of life. Bergstrand and Gemzell2measured pregnanediol excretion in children between the ages of 3 and 15 years but have published no information during the neonatal period.2Utilizing the method of Klopper, an average value of 730 ± 50μg was found in 85 normal children. This finding contrasted with those of Talbot et al3and Balassi and Ricca,4who reported that no pregnanediol could be found in the urine of children.3,4Only one previous report appears in the literature utilizing the method of gas liquid chromatography for analysis of urinary pregnanediol in newborn infants.

CALCIUM AND PHOSPHORUS LEVELS IN HEALTHY NEWBORN INFANTS GIVEN VARIOUS TYPES OF MILK

The influence on the calcium and phosphorus levels of healthy newborn infants of feeding various commonly used milk mixtures has been investigated in 198 healthy term infants. Plasma calcium and phosphorus levels were estimated on the sixth day of life and comparisons were made between infants fed with full-cream and half-cream " unadapted " milks (evaporated and dried), " adapted " milks (' SMA' and ' S26') with breast-fed infants as controls. In breast-fed babies phosphorus levels were lower and calcium levels higher than in babies fed on unadapted cow's milk mixtures. With adapted milks both levels were closer to the values found in breast-fed infants. It is recommended that adjustment, during manufacture, of the phosphorus content of cow's milk products for infants to a value close to that of human milk be considered.

"Small for Dates" Infants have Lower Average Serum Bilirubin Concentrations than Normal Low Birth Weight Infants of Similar Weight

Many factors are known to influence physiologic jaundice in premature infants. However no studies have been reported of the effect intra-uterine growth retardation or malnutrition has upon the average serum bilirubin concentrations in "small for dates" infants. It has been a policy in the nurseries of the University of Vermont Hospitals to do serum bilirubins on all low birth weight infants (2,500 gm or less) on the fourth to sixth day of life. Any infant with a positive Coomb's test or clinical evidence of A.B.O. incompatibility was excluded from this review.

The Development of the Intestinal Flora of the Young Chick

THE bacterial flora of the chick’s intestinal tract has been studied by many workers. Most of these studies have been concentrated on the cecal flora of 8–12 week old birds. An entirely different aspect of the problem was presented by the investigations of Eyssen and DeSomer (1963). They showed that the most significant changes in young chicks occurred around the sixth day of life and were manifest by an inexplicable decrease in rate of gain accompanied by a decreased intestinal absorption of fats and carbohydrates. Addition to the diet of 20 p.p.m. virginiamycin increased the rate of gain and prevented the malabsorption of fats and carbohydrates. Pensack (1963) verified the results of Eyssen and DeSomer (1963) and showed that other antibiotics, such as chlortetracycline and penicillin, were effective in overcoming the malabsorption syndrome.This investigation was conducted to study the microflora of young chicks undergoing this malabsorption syndrome and…

Concentration of fibrinogen in the plasma of healthy and of erythroblastotic and hyperbilirubinemic newborn infants.

SummaryThe concentration of fibrinogen in the plasma of 39 infants during the neonatal period was determined by Morrison's syneresis method as modified by Blom‐back. The samples were drawn from the umbilical vein by catheterization. The results, expressed in mean and standard error of the mean, were as follows:A. Healthy full‐term infants at birth: 225 ± 10.0 mg/100 ml.B. Healthy full‐term infants during third to sixth day of life: 322 ± 21.2 mg/100 ml.C. Erythroblastotic infants at birth: 271 ± 14.7 mg/100 ml.D. Hyperbilirubinemic infants without blood‐group incompatibility during third to sixth day of life: 297 ± 30.0 mg/100 ml.No statistically significant difference was found between healthy and erythroblastotic or hyperbilirubinemic infants as regards concentration of fibrinogen in the plasma.

Ear studies in the newborn infant: II. Age of spontaneous visibility of the auditory canal and tympanic membrane, and the appearance of these structures in healthy newborn infants

Summary In 524 examinations of ears during the first week of life in healthy full-term infants, 191 ears were adequately visualized without cleansing. The progressive spontaneous clearing of vernix is evidenced by the finding of 169 visible drums in 316 examinations (53.5 per cent) of newborn infants on their fourth to sixth days of life, compared to only 22 visualizations in 208 examinations (10.5 per cent) in the first 3 days of life. The normal landmarks in the immediate postnatal period are described. Ear drums become less reddened after the first 24 hours and landmarks become clearer, but the ear drums are pinker and the landmarks less distinct than in the older child. New features described are the dorsal and ventral “fireballs,” spokelike markings, and a dorsal gray area.

Histopathology of Erythema Toxicum Neonatorum

Erythema toxicum neonatorum is a common condition, occurring in approximately one-third of the infants examined by Taylor and Bondurant.1These authors gave the first presentation of this disease in the American dermatological literature, emphasized that erythema toxicum neonatorum is a definite disease entity, and gave an excellent description of the clinical picture. The disease appears within the first three to four days of life as erythematous macules, papules, pustules, or combinations of these lesions. The eruption generally disappears by the sixth day of life. Luders2recently reported the first description of the histologic changes that occur with the disease. The present paper presents our histopathologic findings in 10 cases. Material and Methods The present study was performed on biopsy tissues obtained from 10 erythema toxicum neonatorum patients showing typical erythematous, papular, or pustular lesions. Cases were selected to show early and late lesions of all forms, including

HYPERBILIRUBINEMIA IN INFANTS

To the Editor:— Recently we became aware of an association between the administration of large amounts (72 mg.) of a vitamin K analogue, menadione sodium bisulfite (Hykinone), intravenously to mothers in labor and the occurrence of marked, early hyperbilirubinemia in newborn premature infants. We have encountered seven such cases, the details of which are listed in the table. These infants were first noted to have markedly elevated levels of serum bilirubin between 40-72 hours of age. All but one were treated with exchange transfusionin an effort to prevent neurological damage (kernicterus) from the hyperbilirubinemia. Under ordinary conditions jaundice of this degree does not occur until the fourth to sixth day of life. There is adequate evidence in the literature to show that vitamin K analogues are capable of causing hyperbilirubinemia when administered in large amounts to premature infants. Inasmuch as doses as small as 1-10 mg. given by

Ear studies in the newborn infant: Natural appearance and incidence of obscuring by vernix, cleansing of vernix, and description of drum and canal after cleansing

Summary In 524 examinations of ears during the first week of life in healthy full-term infants, 191 ears were adequately visualized without cleansing. The progressive spontaneous clearing of vernix is evidenced by the finding of 169 visible drums in 316 examinations (53.5 per cent) of newborn infants on their fourth to sixth days of life, compared to only 22 visualizations in 208 examinations (10.5 per cent) in the first 3 days of life. The normal landmarks in the immediate postnatal period are described. Ear drums become less reddened after the first 24 hours and landmarks become clearer, but the ear drums are pinker and the landmarks less distinct than in the older child. New features described are the dorsal and ventral fireballs, spokelike markings, and a dorsal gray area.

STUDIES OF RESPIRATORY INSUFFICIENCY IN NEWBORN INFANTS

A birth weight of 1,750 grams served in the present study to separate premature infants with a good chance of survival from those confronted by grave risks. The fatality rate among infants above this weight was about 2% and for infants below this weight it was about 25%. Severe respiratory disturbances occurred in about 20% of infants with birth weights over 1,750 gm and in about 80% of infants under this weight. Initial apnea and bradypnea occurred among the heavier weight group, but the survival rate among such infants was good. In contrast, among infants in the lower weight group, initial apnea and bradypnea were associated with a high incidence of severe respiratory disturbances and a high fatality rate. Deaths in the first week of life were not observed among 248 premature infants whose respiratory rates did not increase significantly after the first hour, but death did occur in 23 of 102 premature infants who had significant increases in the respiratory rates on the first day or two after birth. Twenty-seven of sixty-one infants with birth weights from 1,001 to 1,750 gm survived without oxygen therapy; 9 of these 27 infants weighed less than 1,501 gm at birth; the smallest had a birth weight of 1,225 gm. The results suggest that oxygen therapy can be withheld with some confidence in the case of infants with birth weights from 1,001 to 1,750 gm, provided the infants (1) are free of cyanosis within a few minutes of birth, (2) initiate sustained, spontaneous respirations within 2 minutes of birth, (3) attain a respiratory rate of 40/min or more during the first hour, and (4) do not have a significant increase in respiratory rates after the first hour. No deaths occurred among 13 infants who fulfilled the above criteria; only one received oxygen therapy and this was begun on the sixth day of life because of pneumonia. The incidence of oxygen therapy, and of deaths, was very high among infants with birth weights from 1,001 to 1,750 gm who did not fulfill the above criteria. Fourteen of nineteen infants with initial apnea, and 10 of 11 infants with initial bradypnea, received oxygen therapy, and about 50% in each group died. None of the six infants who had both initial apnea and bradypnea survived, although all received oxygen therapy. There were 24 infants who did not have initial apnea or bradypnea, but did have a significant increase in the respiratory rates; 16 received oxygen therapy and 3 died. The indications for discontinuing oxygen therapy were difficult to determine for infants with birth weights less than 1,751 gm. These infants, if they belonged to respiratory Group III, often developed sudden, unexpected bradypnea and apnea after apparently recovering from the initial respiratory disturbances of the first 2 days. Late bradypnea and apnea were associated in this study with a fatality rate of about 60% among infants with birth weights under 1,751 gm. The criteria for discontinuing oxygen therapy in small premature infants will continue to be indefinite until some means is found for predicting the occurrence of late, severe bradypnea and apnea with greater accuracy than is at present available.

Absence of a Lansing effect in Drosophila subobscura.

LANSING1 has conducted experiments to show the effect of maternal age on the length of life of the parthenogenetic rotifer Philodina citrina. The median length of life of the ‘wild’ strain of this species was 21–24 days, and maximum length and the adult rate of egg production were reached on the sixth day of life. A strain was bred from this wild strain consisting of rotifers hatched in each generation from eggs laid on the fourth day of parental life. Other strains were established, with parental ages in each generation of eleven and of sixteen days. In the fourth-day strain, the mean expectation of life increased over several generations, and the age of attaining the adult rate of egg production was delayed. In the eleventh- and sixteenth-day strains, there was a rapid decrease in the mean expectation of life, the strains reaching extinction in five and three generations respectively. According to Lansing, longevity progressively declines in any strain which is maintained in each generation from eggs laid on or after the sixth day of life. Results similar to those given by Philodina were also obtained by Lansing with Euchlanis triquetra.

The relation of breast feeding prognosis to the initial amount of maternal milk.

SummaryIn a series of 1836 consecutive cases of infants with a birth weight of 3000 g or more, who had not shown any manifest defects during the first week of life and who after discharge with their mothers to their homes could be followed at least to the age of two months, the duration of breast feeding was compared with the amount of milk produced by the mother on the infant's sixth day of life. Duration of breast feeding was reckoned as the total time until the infant was definitely weaned from the breast. Those infants where the mother had delivered 200 ml of milk or less on the sixth day suffered considerably shorter periods of breast feeding than the rest, 44.1 per cent being weaned before 2 months of age against 6.6–0.6 per cent in the other groups, and only 22.1 per cent being breast fed for at least 6 months, as against 50–80 per cent in the groups with higher initial lactation. Those infants where the mother had been able to pump out at least 100 ml of milk beyond what the infant had sucked itself, were breast fed for a considerably longer time than the mean of the total series, and this applies to the group where the infant had been able to suck itself at least 300 ml as well as to the group where the infant had sucked not more than 200 ml. It seems, therefore, as if it would be possible to improve the prognosis of breast feeding in many cases by regular manual emptying of the breasts.

Early clamping of the umbilical cord during cesarean section

Summary 1.Red cell counts and hemoglobin levels were determined in twenty-eight infants, born by cesarean section, whose cords were clamped immediately after delivery of the infant. Observations were made on the first, the third or fourth, and the fifth or sixth days of life. Counts and levels were similarly determined on a control series of twenty-six infants, born uneventfully by the vaginal route, whose cords were also clamped immediately. 2.The red cell counts and hemoglobin levels of the section infants were slightly lower than those of the control infants (just achieving statistical significance) when figures for the same day were compared. 3.The control infants, with their slight neonatal excess of blood, showed a greater fall of red cell and hemoglobin values in their first week until their fifth- and sixth-day readings approached those of the section infants. 4.The control infants showed a greater incidence of jaundice. 5.The failure of red cell counts and hemoglobin levels to reflect the section infant's blood loss when his cord is clamped immediately suggests that his contracting spleen compensates for any deficit, since it is known that his plasma volume is usually corrected within a few minutes. 6.Evidence of greater hemolysis of the control infant's neonatal excess of red cells, and realization that the newborn infant has a considerably smaller vascular bed than the fetus at term, suggests that a placental blood loss, caused by immediate clamping of the umbilical cord, may relieve the infant of a plethora of blood. 7.The data presented here do not substantiate the theory that immediate clamping of the umbilical cord during cesarean section results in critical blood loss or fatal shock.